Sub Unit A-Parts: It is the first part attached on the RVR-00. This unit includes the Over Weapon cannon, an Enhanced Radar dish, and Warp Engine used by the Phoenix to warp-cruise.

Sub Unit B-Parts: Booster Engine, it's attached behind the A-Parts, ostensibly used for reaching orbit. Apparently is also the Power Plant of the Over Weapon used as the Phoenix Brigandine. Once it's detached it can also usable as a high-explosive device.

The Sub Units of the Phoenix only make an appearance in the Opening and Phoenix Take Off cutscenes. During both sequences, the Sub Unit B is used to launch the Phoenix Brigandine into space to support the Sword Fleet against the ORN forces. The RVR-00 detaches from the B-Parts, which detontates in the midst of the battle, inflicting heavy damages on the ORN fleet. As the RVR-00 leaves the battlefield and activates the Warp Engine heading to the Galaxy Federation homeworld, then the A-Parts detach from the Phoenix, leaving the Over Weapon Photon Rifle and the Radar dish equipped on the ship.